i had installed zorin but after i restarted the laptop it goes to bios mode and nothing operating systems(os) detected to boot
(i deleted windows boot manager previously)
please solve this problem, because i want replace my windows 10 to zorin os
If something went wrong during the last time you installed it, I think the easiest option to fix this issue would be a fresh installation of Zorin OS. Just make sure to tell the installer to use the entire drive so that it overwrites everything in it, effectively removing W10 and using the entire drive for Zorin OS.
The default settings should take care of that automatically, so there's no need to mess with any settings unless you want to have a more specialized set up.
Have you disabled Fast Boot and Secure Boot in the BIOS? If you are still having issues, I notice you have Zorin Pro which entitles you to support from Zorin. You just need to fill out the request form here:
In the rare instance you are using a computer which has the HP Thin OS and their weird bios (so you upgraded the default m.2 memory and then discovered it won't look for other drives,
If you are using a computer/hp thin pro/thin client
You'll need to keep the original OS installed for the bios to play nice with and boot other operating systems.
(But I doubt this is the case)
You can also use a live USB,
Click on try Zorin
Pop open the terminal and run
Sudo uodate-grub
Then restart and remove the live USB and it should* fingers crossed do something 
Make sure that in your BIOS/UEFI ubuntu (that is Zorin) is on the first position of the boot options.
When it doesn't boot you can try to switch between UEFI and legacy/CSM and look if that helps.
Another option you have is to boot from Zorin USB Boot stick and choose "Try Zorin" and then search in the start menu for system tools >boot repair and start it.
So, at the Moment, You still have Windows 10 installed, yes? And only delete the Boot Manager?
If You want to replace Windows, You could now simply do that. If You have the USB Stick with Zorin on it, start it and install it. Choose during the Installation the Option ''Erase Disk''. That will completely wipe Your whole Drive and install automatically Zorin.
If You need to save Data, You could use the ''Try Zorin'' Mode with the Zorin USB Stick, open Nautilus (the File Manager), go to ''Other Places'' and navigate to Windows and Zorin and copy and save Your Data on an external Drive.
If this goes too far for You and You're not ready for this and You want keep Your Dual-Boot:
Start the Zorin USB Stick, choose ''Try Zorin'' and in the Live Mode look for the Program ''Boot Repair''. Let it run and then look if You get a GRUB Menu.